Mesh bag fusion cage
The nested structure of the outer mesh bag and the inner mesh bag solves the problem of insufficient strength of the existing fusion device, and achieves the effects of high stability, small size and light weight after expansion.
Patent Information
- Application Number
- CN202510788325.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-10-10
AI Technical Summary
Existing expandable fusion devices have low strength, are easily deformed or damaged by external forces, and have poor stability.
The outer mesh bag and the inner mesh bag are nested in a structure, and a double-layer mesh bag support is formed by the engagement of the limiting boss and the limiting recess. The lines of the outer mesh bag and the inner mesh bag are staggered to ensure that they will not be deformed or damaged after being stretched, and have good stability.
It can withstand large external forces without deformation or damage after being expanded, is small in size, light in weight, and has good stability, which reduces the burden on users.
Smart Images
Figure CN120753839A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of medical devices, and in particular to a mesh bag fusion device. Background Art
[0002] Spinal fusion is a surgical procedure that connects or fuses two or more vertebrae. It requires the use of an intervertebral fusion cage, an artificial prosthesis that restores and supports the space between the two vertebrae. Currently, expandable cages are popular. These cages are typically made of biocompatible metal materials and have a mesh bag structure. A tool can be used to squeeze the mesh bag, causing it to deform and expand.
[0003] However, the existing fusion devices of this type have low overall strength and are prone to deformation, collapse or even damage due to external forces after being expanded, resulting in poor stability. Summary of the Invention
[0004] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a mesh bag fusion device. Compared with the existing technology, the mesh bag fusion device has higher strength, can withstand large external forces without deformation or damage after being expanded, and has good stability.
[0005] The purpose of the present invention is achieved by adopting the following technical solutions: A mesh bag fusion device comprises an outer mesh bag and an inner mesh bag for being nested inside the outer mesh bag; The outer mesh bag includes an outer bottom ring, an outer mesh body and an outer top ring. The two ends of the outer mesh body are coaxially connected to the outer bottom ring and the outer top ring respectively. The inner side wall of the outer bottom ring is provided with a limiting boss. The inner mesh bag comprises an inner bottom ring, an inner mesh body and an inner top ring. The two ends of the inner mesh body are coaxially connected to the inner bottom ring and the inner top ring respectively. The inner bottom ring is provided with a limited notch. The limiting boss is used to engage with the limiting recess to prevent the inner mesh bag from rotating relative to the outer mesh bag, and when the limiting boss is engaged with the limiting recess, the position of the inner bottom ring corresponds to the position of the outer bottom ring, the position of the inner mesh body corresponds to the position of the outer mesh body, and the position of the inner top ring corresponds to the position of the outer top ring.
[0006] Furthermore, the outer layer mesh body is in a circular tube shape in an initial state; the inner layer mesh body is in a circular tube shape in an initial state.
[0007] Furthermore, the outer bottom ring and the outer top ring are used to squeeze the outer mesh from both ends of the outer mesh, thereby expanding the outer mesh; the inner bottom ring and the inner top ring are used to squeeze the inner mesh from both ends of the inner mesh, thereby expanding the inner mesh.
[0008] Furthermore, the outer mesh layer is in an ellipsoidal shape when in the expanded state; and the inner mesh layer is in an ellipsoidal shape when in the expanded state.
[0009] Furthermore, the outer layer mesh includes a first outer layer wire body and a second outer layer wire body, the first outer layer wire body is arranged along the axial direction of the outer layer mesh body, the second outer layer wire body is arranged along the circumferential direction of the outer layer mesh body, a plurality of first outer layer wire bodies are provided and are spaced apart along the circumferential direction of the outer layer mesh body, a plurality of second outer layer wire bodies are provided and are spaced apart along the axial direction of the outer layer mesh body, and the first outer layer wire body and the second outer layer wire body are connected together at the intersection; In the initial state of the outer mesh, the first outer layer wire body is in a straight line shape, and the second outer layer wire body is in a folded shape. In the expanded state of the outer mesh, the first outer layer wire body is in a curved shape convex radially outward from the outer mesh body, and the second outer layer wire body is in an expanded shape. The inner layer mesh body includes a first inner layer wire body and a second inner layer wire body, the first inner layer wire body is arranged along the axial direction of the inner layer mesh body, the second inner layer wire body is arranged along the circumferential direction of the inner layer mesh body, a plurality of first inner layer wire bodies are provided and are spaced apart along the circumferential direction of the inner layer mesh body, a plurality of second inner layer wire bodies are provided and are spaced apart along the axial direction of the inner layer mesh body, and the first inner layer wire body and the second inner layer wire body are connected together at the intersection; In the initial state of the inner layer mesh, the first inner layer wire body is straight and the second inner layer wire body is folded. In the expanded state, the first inner layer wire body is curved and convex radially outward from the inner layer mesh body, and the second inner layer wire body is unfolded.
[0010] Furthermore, when the limiting boss is engaged with the limiting recess, the first outer layer wire body and the first inner layer wire body are arranged in a staggered manner, and the second outer layer wire body and the second inner layer wire body are arranged in a staggered manner.
[0011] Furthermore, the limiting boss is provided with a screw thread at one end facing the axis of the outer bottom ring; when the limiting boss is engaged with the limiting recess, the end of the limiting boss provided with the screw thread extends into the inner side of the inner bottom ring.
[0012] Furthermore, a screw boss is provided on the inner side wall of the inner bottom ring, and a screw boss is provided with screw threads at one end facing the axis of the inner bottom ring, and the screw threads of the screw boss match the screw threads of the limiting boss.
[0013] Furthermore, the outer layer mesh bag also includes an outer layer bag opening coaxially connected to the outer layer top ring, the outer layer bag opening is a mesh structure and can be squeezed and expanded, the outer layer bag opening and the outer layer mesh are respectively located at the axial ends of the outer layer top ring, in the initial state, the outer layer bag opening is flush with the outer layer top ring, and in the expanded state, the outer layer bag opening is a gradually expanding structure from the end connected to the outer layer top ring to the end facing away from the outer layer top ring; The inner layer mesh bag also includes an inner layer bag opening coaxially connected to the inner layer top ring, the inner layer bag opening is a mesh structure and can be squeezed and expanded, the inner layer bag opening and the inner layer mesh are respectively located at the axial ends of the inner layer top ring, in the initial state, the inner layer bag opening is flush with the inner layer top ring, and in the expanded state, the inner layer bag opening is a gradually expanding structure from the end connected to the inner layer top ring to the end facing away from the inner layer top ring; When the limiting boss is engaged with the limiting recess, the position of the outer bag opening corresponds to the position of the inner bag opening.
[0014] Furthermore, the outer bag opening is in an oblique shape, and the inner bag opening is in an oblique shape; when the limiting boss is engaged with the limiting recess, the direction of the outer bag opening is the same as that of the inner bag opening.
[0015] Compared with the prior art, the present invention has the following beneficial effects: The mesh bag fusion device provided by the present invention realizes a double-layer mesh bag support structure by nesting the outer mesh bag and the inner mesh bag. It has high strength and can withstand large external forces without deformation or damage after being expanded, and has good stability.
[0016] The mesh bag fusion device of the present invention, formed by nesting and cooperating a double-layer mesh bag support, does not result in excessive volume, substantially does not affect the internal space of the fusion device, and does not result in excessive weight. Existing single-layer mesh bag supports require either extremely wide or dense mesh lines to ensure sufficiently small mesh openings. The present invention utilizes a double-layer mesh bag support, which effectively utilizes two layers of relatively loose mesh bags (i.e., each layer is relatively lightweight). The outer and inner mesh bags are nested and stacked together to form a relatively dense mesh structure (which can be understood as a mesh structure with more threads and smaller mesh openings). The outer and inner mesh bags are effectively prevented from rotating relative to each other through the engagement of the limiting bosses and limiting recesses, preventing changes in the density of the mesh structure caused by rotation. Therefore, the double-layer mesh bag support provides both stable support and reduced weight.
[0017] In summary, the mesh bag fusion device of the present invention is small in size, light in weight, and high in strength. After being expanded, it can withstand large external forces without deformation or damage, has good stability, and helps to reduce the burden on users. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic structural diagram of an outer mesh bag according to an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 for Figure 1The bottom structure diagram of the outer mesh bag shown; Figure 4 This is a schematic structural diagram of an inner mesh bag according to an embodiment of the present invention; Figure 5 for Figure 4 Enlarged view of point B in the middle; Figure 6 for Figure 4 The bottom structure diagram of the inner mesh bag shown; Figure 7 This is a schematic structural diagram of a mesh bag fusion device according to an embodiment of the present invention; Figure 8 for Figure 7 A top view of the mesh bag fusion device is shown; Figure 9 for Figure 7 The bottom structure diagram of the mesh bag fusion device is shown; Figure 10 This is a schematic diagram of a mesh bag fusion device according to an embodiment of the present invention.
[0019] In the picture: 100, outer mesh bag; 110, outer bottom ring; 111, limiting boss; 120, outer mesh body; 121, first outer line body; 122, second outer line body; 130, outer top ring; 140, outer bag opening; 200, inner mesh bag; 210, inner bottom ring; 211, limiting notch; 212, screw boss; 220, inner mesh body; 221, first inner line body; 222, second inner line body; 230, inner top ring; 240, inner bag opening. DETAILED DESCRIPTION
[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.
[0021] refer to Figures 1-10 An embodiment of the present invention provides a mesh bag fusion device, comprising an outer mesh bag 100 and an inner mesh bag 200 for being nested inside the outer mesh bag 100 .
[0022] The outer mesh bag 100 includes an outer bottom ring 110, an outer mesh body 120 and an outer top ring 130. The two ends of the outer mesh body 120 are coaxially connected to the outer bottom ring 110 and the outer top ring 130 respectively. A limiting boss 111 is provided on the inner side wall of the outer bottom ring 110.
[0023] The inner mesh bag 200 includes an inner bottom ring 210 , an inner mesh body 220 and an inner top ring 230 . The two ends of the inner mesh body 220 are coaxially connected to the inner bottom ring 210 and the inner top ring 230 respectively. The inner bottom ring 210 is provided with a limiting notch 211 .
[0024] In the mesh bag fusion device of the embodiment of the present invention, the limiting boss 111 is used to engage with the limiting recess 211 to prevent the inner mesh bag 200 from rotating relative to the outer mesh bag 100. When the limiting boss 111 engages with the limiting recess 211, the position of the inner bottom ring 210 corresponds to the position of the outer bottom ring 110, the position of the inner mesh body 220 corresponds to the position of the outer mesh body 120, and the position of the inner top ring 230 corresponds to the position of the outer top ring 130. Specifically, the outer mesh body 120 is in a circular tubular shape in the initial state, and the inner mesh body 220 is in a circular tubular shape in the initial state; the outer mesh body 120 is in an ellipsoidal shape in the expanded state; and the inner mesh body 220 is in an ellipsoidal shape in the expanded state, although a spherical shape is also within the range of the ellipsoidal shape. The initial state herein refers to the state in which the outer mesh 120 or the inner mesh 220 has not been expanded by the expansion tool, and the expanded state herein refers to the state in which the outer mesh 120 or the inner mesh 220 has been expanded by the expansion tool. The cylindrical shape in the initial state and the ellipsoidal shape in the expanded state are only one embodiment of the present invention, and in practice, different cross-sectional shapes may be employed.
[0025] The mesh bag fusion device provided in the embodiment of the present invention realizes a double-layer mesh bag support structure by nesting the outer mesh bag and the inner mesh bag. It has high strength and can withstand large external forces without deformation or damage after being expanded, and has good stability.
[0026] The mesh bag fusion device of the present invention, formed by nesting and cooperating in a double-layer mesh bag support, does not result in excessive volume, substantially does not affect the internal space of the fusion device, and does not result in excessive weight. The reason why this does not result in excessive weight can be understood as follows: To ensure sufficiently small mesh openings, the single-layer mesh bag support of the prior art either requires the mesh bag to have extremely wide or extremely dense threads. The present invention, however, utilizes a double-layer mesh bag support, which effectively utilizes two layers of relatively loose mesh bags (i.e., each layer of mesh bags is relatively light). The outer and inner mesh bags are nested and stacked together to form a relatively dense mesh structure (which can be understood as a mesh structure with more threads and smaller mesh openings). The outer and inner mesh bags are effectively prevented from rotating relative to each other through the engagement of the limiting bosses and limiting recesses, preventing changes in the density of the mesh structure due to rotation. Therefore, the double-layer mesh bag support provides both stable support and low weight.
[0027] For example, an embodiment of the present invention may adopt the following network structure.
[0028] In the mesh bag fusion device of an embodiment of the present invention, the outer layer mesh 120 includes a first outer layer wire 121 and a second outer layer wire 122. The first outer layer wire 121 is arranged along the axial direction of the outer layer mesh 120, and the second outer layer wire 122 is arranged along the circumferential direction of the outer layer mesh 120. There are multiple first layer wires 121 and they are arranged at intervals along the circumference of the outer layer mesh 120. There are multiple second layer wires 122 and they are arranged at intervals along the axial direction of the outer layer mesh 120. The first outer layer wire 121 and the second outer layer wire 122 are connected together at the intersection; in this way, the first outer layer wire 121 and the second outer layer wire 122 form a criss-cross distribution similar to longitude and latitude lines. In the initial state of the outer mesh 120, the first outer layer 121 is straight, and the second outer layer 122 is folded. The second outer layer 122 actually has a wavy curve. When the outer mesh 120 is expanded, the first outer layer 121 is curved and convex radially outward from the outer mesh 120, while the second outer layer 122 is expanded. During the expansion process, the first outer layer 121 convex radially outward, causing the distance between the first outer layer 121 and the second outer layer 122 to increase, thereby causing the second outer layer 122 to be pulled from the folded state to the expanded state. It can be seen that the maximum expansion range of the second outer layer 122 actually limits the maximum expansion range of the outer mesh 120.
[0029] In the mesh bag fusion device of the embodiment of the present invention, the inner layer mesh body 220 includes a first inner layer wire body 221 and a second inner layer wire body 222. The first inner layer wire body 221 is arranged along the axial direction of the inner layer mesh body 220, and the second inner layer wire body 222 is arranged along the circumferential direction of the inner layer mesh body 220. The first inner layer wire body 221 is provided with a plurality of and is spaced apart along the circumference of the inner layer mesh body 220. The second inner layer wire body 222 is provided with a plurality of and is spaced apart along the axial direction of the inner layer mesh body 220. The first inner layer wire body 221 and the second inner layer wire body 222 are connected together at the intersection. In the initial state of the inner layer mesh body 220, the first inner layer wire body 221 is straight and the second inner layer wire body 222 is folded. In the expanded state of the inner layer mesh body 220, the first inner layer wire body 221 is curved and convex radially outward from the inner layer mesh body 220, and the second inner layer wire body 222 is expanded.
[0030] Regarding how the above-mentioned outer mesh 120 and inner mesh 220 are stacked into a relatively dense mesh structure, the adopted design is: when the limiting boss 111 is engaged with the limiting recess 211, the first outer wire 121 and the first inner wire 221 are staggered, and the second outer wire 122 and the second inner wire 222 are staggered; that is, the embodiment of the present invention enables the outer mesh 120 and the inner mesh 220 to form a stable staggered assembly through the engagement of the limiting boss 111 and the limiting recess 211, so that the wires of the outer mesh 120 and the inner mesh 220 can be fully utilized to jointly form a relatively dense mesh structure.
[0031] The mesh bag fusion device of the embodiment of the present invention can be expanded by airbag expansion or by screw propulsion, both of which are relatively common expansion methods. When using screw propulsion to expand, the mesh body is actually squeezed from both ends of the outer mesh body 120 or the inner mesh body 220 to expand. In the embodiment of the present invention, the outer bottom ring 110 and the outer top ring 130 are used to squeeze the outer mesh body 120 from both ends of the outer mesh body 120 to expand the outer mesh body 120; the inner bottom ring 210 and the inner top ring 230 are used to squeeze the inner mesh body 220 from both ends of the inner mesh body 220 to expand the inner mesh body 220.
[0032] To facilitate the use of a screw for expansion, a screw thread structure must be designed into the fusion device. Specifically, in the mesh bag fusion device of the present invention, a limiting boss 111 is provided with a screw thread at the end facing the axis of the outer bottom ring 110. When the limiting boss 111 engages with the limiting recess 211, the end of the limiting boss 111 provided with the screw thread extends into the inner side of the inner bottom ring 210. This design allows the screw of the expansion tool to be inserted into the inner mesh bag 200. The screw and limiting boss 111 form a threaded transmission, shortening the gap between the outer bottom ring 110 and the outer top ring 130, thereby squeezing the ends of the outer mesh body 120. Furthermore, the limiting boss 111 can also drive the displacement of the inner bottom ring 210, thereby effectively shortening the gap between the inner bottom ring 210 and the inner top ring 230, thereby squeezing the ends of the inner mesh body 220.
[0033] Although only providing screw threads on the outer bottom ring 110 can simultaneously achieve the expansion of the outer mesh body 120 and the inner mesh body 220, it will cause the outer bottom ring 110 to be subjected to excessive force, which can easily lead to an unsmooth expansion process or damage. Therefore, in the mesh bag fusion device of the embodiment of the present invention, the inner side wall of the inner bottom ring 210 is provided with a screw thread boss 212, and the screw thread boss 212 is provided with a screw thread at one end facing the axis of the inner bottom ring 210, and the screw thread of the screw thread boss 212 matches the screw thread of the limiting boss 111; matching here means that the screw threads of both can simultaneously form a threaded transmission match with the screw rod of the expansion tool, so that the expansion tool can simultaneously apply force to the outer bottom ring 110 and the inner bottom ring 210, making the expansion process smoother and avoiding damage to the fusion device.
[0034] In the mesh bag fusion device of the embodiment of the present invention, the outer mesh bag 100 also includes an outer bag mouth 140 coaxially connected to the outer top ring 130. The outer bag mouth 140 has a mesh structure and can be squeezed and expanded. The outer bag mouth 140 and the outer mesh body 120 are respectively located at the axial ends of the outer top ring 130. In the initial state, the outer bag mouth 140 is flush with the outer top ring 130 (it can be understood that the outer side surface of the bag mouth is flush with the outer side surface of the top ring). In the expanded state, the outer bag mouth 140 has a gradually expanding structure from one end connected to the outer top ring 130 to the end facing away from the outer top ring 130, that is, the outer bag mouth 140 forms a shape similar to a funnel. The inner mesh bag 200 also includes an inner bag opening 240 coaxially connected to the inner top ring 230. The inner bag opening 240 has a mesh structure and can be squeezed and expanded. The inner bag opening 240 and the inner mesh 220 are located at the axial ends of the inner top ring 230, respectively. In the initial state, the inner bag opening 240 is flush with the inner top ring 230. In the expanded state, the inner bag opening 240 gradually expands from the end connected to the inner top ring 230 to the end facing away from the inner top ring 230. When the limiting boss 111 engages with the limiting recess 211, the position of the outer bag opening 140 corresponds to the position of the inner bag opening 240. The structure of the outer bag opening 140 and the inner bag opening 240 in the expanded state helps the surgeon find the entrance to the fusion device and facilitates the placement of surgical materials inside the fusion device.
[0035] In the mesh bag fusion device of the embodiment of the present invention, the outer bag opening 140 is oblique, and the inner bag opening 240 is oblique; when the limiting boss 111 is engaged with the limiting recess 211, the direction of the outer bag opening 140 is the same as that of the inner bag opening 240. The directions here are the same, which can be understood as follows: the outer bag opening 140 has a higher side and a lower side due to its oblique shape, and the inner bag opening 240 also has a higher side and a lower side; when the outer bag opening 140 and the inner bag opening 240 are in the same direction, it means that the higher side of the outer bag opening 140 corresponds to the higher side of the inner bag opening 240, and the lower side of the outer bag opening 140 corresponds to the lower side of the inner bag opening 240; in this way, the bag opening can play a role in indicating the direction. When the inner mesh bag 200 is loaded into the outer mesh bag 100, the direction of the inner bag opening 240 can be adjusted to be consistent with the direction of the outer bag opening 140, thereby ensuring that the position of the limiting recess 211 can correspond to the position of the limiting boss 111, so that the two are accurately engaged together.
[0036] Specifically, the outer layer bag opening 140 and the inner layer bag opening 240 may adopt a linear distribution structure similar to that of the outer layer mesh 120 and the inner layer mesh 220 .
[0037] In summary, the mesh bag fusion device of the present invention is small in size, light in weight, and high in strength. After being expanded, it can withstand large external forces without deformation or damage. It has good stability and helps to reduce the burden on users. It is also simple and convenient to use.
[0038] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.
Claims
1. A mesh bag fusion device, characterized in that: The invention comprises an outer mesh bag and an inner mesh bag for being nested inside the outer mesh bag; The outer mesh bag includes an outer bottom ring, an outer mesh body and an outer top ring. The two ends of the outer mesh body are coaxially connected to the outer bottom ring and the outer top ring respectively. The inner side wall of the outer bottom ring is provided with a limiting boss. The inner mesh bag comprises an inner bottom ring, an inner mesh body and an inner top ring. The two ends of the inner mesh body are coaxially connected to the inner bottom ring and the inner top ring respectively. The inner bottom ring is provided with a limited notch. The limiting boss is used to engage with the limiting recess to prevent the inner mesh bag from rotating relative to the outer mesh bag, and when the limiting boss is engaged with the limiting recess, the position of the inner bottom ring corresponds to the position of the outer bottom ring, the position of the inner mesh body corresponds to the position of the outer mesh body, and the position of the inner top ring corresponds to the position of the outer top ring.
2. The mesh bag fusion device according to claim 1, characterized in that: The outer layer mesh body is in a circular tube shape in an initial state; the inner layer mesh body is in a circular tube shape in an initial state.
3. The mesh bag fusion device according to claim 1, characterized in that: The outer bottom ring and the outer top ring are used to squeeze the outer mesh from both ends of the outer mesh, thereby expanding the outer mesh; the inner bottom ring and the inner top ring are used to squeeze the inner mesh from both ends of the inner mesh, thereby expanding the inner mesh.
4. The mesh bag fusion device according to claim 1, characterized in that: The outer mesh body is in an ellipsoidal shape when in the expanded state; the inner mesh body is in an ellipsoidal shape when in the expanded state.
5. The mesh bag fusion cage according to claim 1, characterized in that: The outer layer mesh includes a first outer layer wire body and a second outer layer wire body, the first outer layer wire body is arranged along the axial direction of the outer layer mesh body, the second outer layer wire body is arranged along the circumferential direction of the outer layer mesh body, a plurality of first outer layer wire bodies are provided and are spaced apart along the circumferential direction of the outer layer mesh body, a plurality of second outer layer wire bodies are provided and are spaced apart along the axial direction of the outer layer mesh body, and the first outer layer wire body and the second outer layer wire body are connected together at the intersection; In the initial state of the outer mesh, the first outer layer wire body is in a straight line shape, and the second outer layer wire body is in a folded shape. In the expanded state of the outer mesh, the first outer layer wire body is in a curved shape convex radially outward from the outer mesh body, and the second outer layer wire body is in an expanded shape. The inner layer mesh body includes a first inner layer wire body and a second inner layer wire body, the first inner layer wire body is arranged along the axial direction of the inner layer mesh body, the second inner layer wire body is arranged along the circumferential direction of the inner layer mesh body, a plurality of first inner layer wire bodies are provided and are spaced apart along the circumferential direction of the inner layer mesh body, a plurality of second inner layer wire bodies are provided and are spaced apart along the axial direction of the inner layer mesh body, and the first inner layer wire body and the second inner layer wire body are connected together at the intersection; In the initial state of the inner layer mesh, the first inner layer wire body is straight and the second inner layer wire body is folded. In the expanded state, the first inner layer wire body is curved and convex radially outward from the inner layer mesh body, and the second inner layer wire body is unfolded.
6. The mesh bag fusion device according to claim 5, characterized in that: When the limiting boss is engaged with the limiting recess, the first outer layer wire body and the first inner layer wire body are arranged in a staggered manner, and the second outer layer wire body and the second inner layer wire body are arranged in a staggered manner.
7. The mesh bag fusion cage according to claim 1, characterized in that: The limiting boss is provided with a screw thread at one end facing the axis of the outer bottom ring; when the limiting boss is engaged with the limiting recess, the end of the limiting boss provided with the screw thread extends into the inner side of the inner bottom ring.
8. The mesh bag fusion device according to claim 7, characterized in that: The inner side wall of the inner bottom ring is provided with a screw boss, and the screw boss is provided with screw threads at one end facing the axis of the inner bottom ring, and the screw threads of the screw boss match the screw threads of the limiting boss.
9. The mesh bag fusion cage according to claim 1, characterized in that: The outer layer mesh bag also includes an outer layer bag opening coaxially connected to the outer layer top ring, the outer layer bag opening is a mesh structure and can be squeezed and stretched, the outer layer bag opening and the outer layer mesh are respectively located at the axial ends of the outer layer top ring, in the initial state, the outer layer bag opening is flush with the outer layer top ring, and in the stretched state, the outer layer bag opening is a gradually expanding structure from the end connected to the outer layer top ring to the end facing away from the outer layer top ring; The inner layer mesh bag also includes an inner layer bag opening coaxially connected to the inner layer top ring, the inner layer bag opening is a mesh structure and can be squeezed and expanded, the inner layer bag opening and the inner layer mesh are respectively located at the axial ends of the inner layer top ring, in the initial state, the inner layer bag opening is flush with the inner layer top ring, and in the expanded state, the inner layer bag opening is a gradually expanding structure from the end connected to the inner layer top ring to the end facing away from the inner layer top ring; When the limiting boss is engaged with the limiting recess, the position of the outer bag opening corresponds to the position of the inner bag opening.
10. The mesh bag fusion cage according to claim 1, characterized in that: The outer bag opening is in an oblique shape, and the inner bag opening is in an oblique shape; when the limiting boss is engaged with the limiting recess, the direction of the outer bag opening is the same as that of the inner bag opening.